U.S. patent number 10,895,244 [Application Number 16/140,900] was granted by the patent office on 2021-01-19 for joint interface for wind turbine rotor blade components.
This patent grant is currently assigned to General Electric Company. The grantee listed for this patent is General Electric Company. Invention is credited to Scott Jacob Huth, Thomas Merzhaeuser, Andrew Mitchell Rodwell.
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United States Patent |
10,895,244 |
Rodwell , et al. |
January 19, 2021 |
Joint interface for wind turbine rotor blade components
Abstract
A rotor blade component for a wind turbine includes a first
structural component, such as a spar cap, formed from a plurality
of stacked pultruded members. A second structural component, such
as a shear web, is fixed to the first structural component at a
joint interface. One or more webs form the joint interface, wherein
each of the webs has a first section bonded between at least two of
the pultruded members in the first structural component and a
second section extending across the joint interface and bonded onto
or into the second structural component.
Inventors: |
Rodwell; Andrew Mitchell
(Greenville, SC), Merzhaeuser; Thomas (Munich,
DE), Huth; Scott Jacob (Greenville, SC) |
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
(Schenectady, NY)
|
Appl.
No.: |
16/140,900 |
Filed: |
September 25, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200095978 A1 |
Mar 26, 2020 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F03D
1/0641 (20130101); F03D 1/0683 (20130101); F05B
2230/23 (20130101); F05B 2280/6003 (20130101) |
Current International
Class: |
F03D
1/06 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
2 217 748 |
|
Aug 2010 |
|
EP |
|
3 360 670 |
|
Aug 2018 |
|
EP |
|
WO 2018/029240 |
|
Feb 2018 |
|
WO |
|
Other References
PCT Search Report and Written Opinion, dated Dec. 20, 2019. cited
by applicant.
|
Primary Examiner: Hansen; Kenneth J
Assistant Examiner: Adjagbe; Maxime M
Attorney, Agent or Firm: Dority & Manning, P.A.
Claims
What is claimed is:
1. A rotor blade component for a wind turbine, the rotor blade
component comprising: a first structural component comprising a
plurality of stacked pultruded members; a second structural
component fixed to a bottom surface of the first structural
component at a joint interface; and at least one web at the joint
interface, the web comprising a first section and a second section;
the first section of the web extending along and bonded to a top
outer surface of the first structural component that is opposite
from the bottom surface of the first structural component and the
second section of the web extending across the joint interface and
bonded to a first side of the second structural component; a second
web having a first section extending along and bonded to a bottom
outer surface of the first structural component and a second
section extending across the joint interface and bonded to a second
side of the second structural component that is opposite to the
first side; and a plurality of additional webs each having a first
section and a second section, wherein the first section of at least
one of the plurality of additional webs is bonded between at least
two of the pultruded members in the first structural component with
the second section extending across the joint interface and bonded
onto or into the second structural component.
2. The rotor blade component of claim 1, wherein the second
sections of multiple ones of the plurality of additional webs
extend alongside and overlap on an outer surface of the second
structural component, the first section of the web overlying the
overlapping second sections of the multiple ones of the plurality
of additional webs.
3. The rotor blade component of claim 1, wherein the second
structural component comprises a plurality of bonded-together
components, the second section of at least one of the plurality of
additional webs extending between two or more of the
bonded-together components.
4. The rotor blade component of claim 1, wherein the pultruded
members are arranged in stacked rows in the first structural
component, the first section of at least one of the plurality of
additional webs extending between adjacent ones of the stacked
rows.
5. The rotor blade component of claim 4, wherein the pultruded
members are further arranged in adjacent columns, wherein the first
section of at least one of the plurality of additional webs extends
between the pultruded members at different height positions in
adjacent ones of the columns.
6. The rotor blade component of claim 1, wherein the pultruded
members are arranged in stacked rows and columns in the first
structural component, the first section of at least one of the
plurality of additional webs weaving between a combination of the
stacked rows and columns with the second section bonded on or into
the second structural component.
7. The rotor blade component of claim 1, wherein the first section
of at least one of the plurality of additional webs is joined to
the first section of another one of the plurality of additional
webs in the first structural component.
8. The rotor blade component of claim 1, wherein the first section
of at least one of the plurality of additional webs comprises a
plurality of branches, each of the branches extending between
different pairs of the pultruded members.
9. The rotor blade component of claim 1, wherein the first
structural component comprises a spar cap, and the second
structural component comprises a shear web.
10. The rotor blade component of claim 9, wherein the shear web is
fixed to an end of the spar cap in a box-beam spar configuration or
is fixed to an intermediate position on the spar cap in an I-beam
spar configuration.
11. A method for fixing a first structural component to a second
structural component at a joint interface within a wind turbine
rotor blade with a plurality of webs, wherein the first structural
component is formed from a plurality of stacked pultruded members
and the second structural component is fixed to a bottom surface of
the first structural component, the method comprising: bonding a
first section of a first one of the plurality of webs onto a top
outer surface of the first structural component that is opposite to
the bottom surface of the first structural component and bonding
the second section across the joint interface and onto an outer
surface of the second structural component; bonding a first section
of a second one of the plurality of webs along the bottom surface
of the first structural component and bonding a second section
across the joint interface and onto an inner surface of the second
structural component that is opposite to the outer surface; and
bonding a plurality of additional webs each having a first section
and a second section, wherein the first section of at least one of
the plurality of additional webs is bonded between at least two of
the pultruded members in the first structural component with the
second section extending across the joint interface and bonded onto
or into the outer surface or the inner surface of the second
structural component.
12. The method of claim 11, wherein the pultruded members are
arranged in stacked rows and columns in the first structural
component, and further comprising weaving the first section of at
least one of the additional webs between a combination of the
stacked rows and columns of the pultruded members.
13. The method of claim 11, wherein the second structural component
comprises a plurality of bonded-together components, the method
comprising bonding the second section of at least one of the
additional webs between two or more of the bonded-together
components in the second structural component.
Description
FIELD
The present subject matter relates generally to wind turbine rotor
blades and, more particularly, to joint structures between
components of the wind turbine rotor blade.
BACKGROUND
Wind power is considered one of the cleanest, most environmentally
friendly energy sources presently available, and wind turbines have
gained increased attention in this regard. A modern wind turbine
typically includes a tower, generator, gearbox, nacelle, and one or
more rotor blades. The rotor blades capture kinetic energy from
wind using known foil principles and transmit the kinetic energy
through rotational energy to turn a shaft coupling the rotor blades
to a gearbox, or if a gearbox is not used, directly to the
generator. The generator then converts the mechanical energy to
electrical energy that may be deployed to a utility grid.
Wind turbine rotor blades generally include a body shell formed by
two shell halves of a composite laminate material. The shell halves
are generally manufactured using molding processes and then coupled
together along the corresponding ends of the rotor blade. In
general, the body shell is relatively lightweight and has
structural properties (e.g., stiffness, buckling resistance, and
strength) which are not configured to withstand the bending moments
and other loads exerted on the rotor blade during operation. In
addition, wind turbine blades are becoming increasingly longer in
order to produce more power. As a result, the blades must be
stiffer and thus heavier so as to mitigate loads on the rotor.
To increase the stiffness, buckling resistance, and strength of the
rotor blade, the body shell is typically reinforced using one or
more structural components (e.g. opposing spar caps with a shear
web configured therebetween) that engage the inner surfaces of the
shell halves. The spar caps may be constructed of various
materials, including but not limited to glass fiber laminate
composites and/or carbon fiber laminate composites. Such materials,
however, can be difficult to control, defect prone, and/or highly
labor intensive due to handling of the dry and pre-preg fabrics and
the challenges of infusing large laminated structures.
As such, spar caps may also be constructed of pre-fabricated,
pre-cured (i.e. pultruded) composites that can be produced in
thicker sections, and are less susceptible to defects. In addition,
the use of pultrusions in spar caps can decrease the weight and may
also increase the strength thereof. Accordingly, the pultruded
composites can eliminate various concerns and challenges associated
with using dry fabric alone. As used herein, the terms "pultruded
composites," "pultrusions," "pultruded members" or similar
generally encompass reinforced materials (e.g. fibers or woven or
braided strands) that are impregnated with a resin and pulled
through a stationary die such that the resin cures or undergoes
polymerization through added heat or other curing methods. As such,
the process of manufacturing pultruded composites is typically
characterized by a continuous process of composite materials that
produces composite parts having a constant cross-section. A
plurality of pultrusions can then be joined together to form the
spar caps and/or various other rotor blade components.
The benefits of using pultruded plates in spar caps have been
realized and spar caps formed using pultrusions usually include
pultrusion-formed layers bonded together via a resin material. More
specifically, spar caps are generally formed of a plurality of
stacked pultruded plates that are bonded together in a mold.
The interface or joint between the spar caps (pultruded or
non-pultruded) and shear web is a critical structural interface for
both box-beam and I-beam spar constructions. With conventional
configurations, this joint relies primarily on the strength of an
adhesive or resin deposited at the interface of the components.
Event with the benefits of pultruded spar caps, the interface
between the spar cap and shear web can be a limiting structural
aspect of the blade.
The art is continuously seeking new and improved methods of
manufacturing rotor blade components and structural elements with
increased strength and decreased weight. A spar configuration
wherein pultruded spar caps can also be integrated into an improved
structural interface between the spar caps and shear webs would be
an advantageous advancement in the art.
BRIEF DESCRIPTION
Aspects and advantages of the invention will be set forth in part
in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
In one aspect, the present disclosure is directed to a rotor blade
component for a wind turbine having an improved joint interface
configuration. The component includes a first structural component
formed from a plurality of stacked pultruded members. In a
particular embodiment, this first structural component may be, for
example, a spar cap. A second structural component is fixed to the
first structural component at a joint interface. This second
structural component may be, for example, a shear web. One or more
webs are used to fix the first and second components together at
the joint interface, each of the webs comprising a first section
and a second section. In one embodiment, the first section of at
least a first one of the plurality of webs extends along and is
bonded to a top outer surface of the stacked pultruded members with
the second section extending across the joint interface and bonded
to the second structural component.
In an additional embodiment, the first section of a second one of
the plurality of webs extends along and is bonded to a bottom outer
surface of the stacked pultruded members with the second section
extending across the joint interface and bonded to the second
structural component.
In addition, in a further embodiment, one or more additional ones
of the webs has a first section bonded between at least two of the
pultruded members in the first structural component and a second
section extending across the joint interface and bonded onto or
into the second structural component.
In an alternate embodiment, the joint interface may be provided by
a plurality of the webs that weave between different ones of the
pultruded members in the first structural component with or without
the webs that extend along the top or bottom outer surfaces of the
stacked pultruded components.
The improved joint interface structure has particular usefulness
when configured between a spar cap and a shear web in a box-beam or
I-beam spar, wherein the spar cap is formed by the pultruded
members and the shear web is a unitary or multi-element component.
However, the joint interface structure is not limited to this use
or location, and may be used between any structural components
within the wind turbine.
The webs may be variously formed. In one embodiment, each web
includes one or layers of a woven or non-woven fabric material that
is sufficiently pliant to weave around the joint interface or
between the pultruded members at the first section and to extend
onto or into the second structural member. The fabric layers may be
bonded between or to the pultruded members with an adhesive or
resin during formation of the first structural member. The fabric
material layers may be bonded between the pultruded members during
a vacuum thermo-forming process.
In a particular embodiment, the fabric material layers may be
impregnated with a resin or adhesive and also serve a primary
purpose of adhering or bonding the pultruded members together to
form the first structural member. In this embodiment, the webs
would extend entirely throughout the width and length of the first
structural member between adjacent rows and/or columns of the
pultruded members.
The second structural component may be a unitary member, wherein
the second section of each of the plurality of webs extends
alongside an outer surface of the second structural component. The
second sections of multiple webs may overlap along the outer
surface of the second structural component.
In an alternate embodiment, the second structural component
comprises a plurality of bonded-together components, wherein the
second section of at least one of the plurality of webs extends
between two or more of the bonded-together components.
The pultruded members may be arranged in various configurations
within the first structural component. For example, the pultruded
members may be arranged in stacked rows in the first structural
component, wherein the first section of at least one of the
plurality of webs is bonded between two adjacent stacked rows. The
first section of at least one of the webs may be bonded between
each of the stacked rows in the configuration.
The pultruded members may be further arranged in adjacent columns
within the first structural member, wherein the first section of at
least one of the plurality of webs is bonded between the pultruded
members at different height positions in adjacent ones of the
columns. This web may weave between the columns at a different
height between adjacent columns.
It should be appreciated that the first section of a plurality of
the webs may weave between any combination of the stacked rows and
columns of pultruded members within the first structural
component.
In certain embodiments, the first sections of multiple webs may be
joined together within the first structural component.
Alternatively, the first section of one or more of the webs may
include a plurality of branches, wherein each branch extends
between different pairs of the pultruded members.
The present disclosure also encompasses various methodologies for
fixing a first structural component, such as a spar cap, to a
second structural component, such as a shear web, with one or more
webs, wherein the first structural component is formed with a
plurality of stacked pultruded members. The method includes bonding
a first section of at least one of the plurality of webs onto a top
outer surface of the stacked pultruded members and bonding the
second section across the joint interface and onto the second
structural component. In a further method embodiment, a first
section of a second one of the webs is bonded onto a bottom outer
surface of the stacked pultruded members and the second section is
bonded across the joint interface and onto the second structural
component.
In addition to the above method or standing alone, an embodiment of
the method may include bonding the first section of one or more of
the webs between at least two of the pultruded members in the first
structural component and bonding the second section across the
joint interface and onto or into the second structural
component.
In a particular embodiment of the method, the first structural
component is a spar cap, and the second structural component is a
shear web.
In a certain embodiment, the method includes bonding the second
section of each of a plurality of webs alongside an outer surface
of the shear web, wherein one or more of the second sections
overlap along the outer surface of the shear web.
The pultruded members may be arranged in stacked rows and columns
in the spar cap, wherein the method includes weaving the first
section of at least one of the plurality of webs between any
combination of the stacked rows and columns of pultruded
members.
The method may include bonding the first section of at least one of
the webs along an outer surface of each of a top and bottom row of
the stacked pultruded members. These webs may also extend alongside
an outer surface of the second structural member.
These and other features, aspects, and advantages of the present
invention will become better understood with reference to the
following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including
the best mode thereof, directed to one of ordinary skill in the
art, is set forth in the specification, which makes reference to
the appended figures, in which:
FIG. 1 illustrates a perspective view of one embodiment of a wind
turbine according to the present disclosure;
FIG. 2 illustrates a perspective view of one of the rotor blades of
FIG. 1;
FIG. 3 illustrates a cross-sectional view of the rotor blade of
FIG. 2 along line 3-3, and particularly illustrates a box-beam spar
with pultruded spar caps;
FIG. 4 illustrates a cross-sectional view of a rotor blade and
particularly illustrates an I-beam spar with protruded spar
caps;
FIG. 5 is a partial cross-section view of an interface junction
between the spar cap and shear web in a box-beam spar configuration
in accordance with aspects of the invention;
FIG. 6 is a partial cross-section view of another embodiment of an
interface junction between the spar cap and shear web in a box-beam
spar configuration;
FIG. 7 is a partial cross-section view of yet another embodiment of
an interface junction between the spar cap and shear web in a
box-beam spar configuration; and
FIG. 8 is a partial cross-section view of an embodiment of an
interface junction between the spar cap and shear web in an I-beam
spar configuration.
DETAILED DESCRIPTION OF THE INVENTION
Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
Generally, the present subject matter is directed to wind turbine
rotor blade components having improved joint interfaces, and
methods of manufacturing the same. Although not limited to such,
the inventive joint interface constructions are particularly useful
for the critical structural interface between the shear web and
spar caps in a spar configuration. As mentioned, with conventional
constructions, this critical interface relies primarily on an
adhesive or resin application at the interface between the end of
the shear web and the spar cap. The novel joint interface
construction in accordance with the present disclosure uses a
plurality of webs, for example fabric material webs, that bridge
the joint. The webs may be bonded to the outer surfaces of the
structural components at the joint interface, and one or more
additional webs may be woven between separate members of the
structural components, such as between pultruded members of a spar
cap. An opposite end section of the webs are bonded along the sides
of the shear web or within the shear web, for example between
individual structural members forming the shear web. This unique
joint interface construction provides a stronger joint capable of
transferring larger loads as compared to the conventional
construction, which in turn enables lighter and less costly blades
or longer blades and blade beam components before reaching material
limits, which can reduce the overall cost of electricity produced
by the wind turbine.
Referring now to the drawings, FIG. 1 illustrates a perspective
view of a horizontal axis wind turbine 10. It should be appreciated
that the wind turbine 10 may also be a vertical-axis wind turbine.
As shown in the illustrated embodiment, the wind turbine 10
includes a tower 12, a nacelle 14 mounted on the tower 12, and a
rotor hub 18 that is coupled to the nacelle 14. The tower 12 may be
fabricated from tubular steel or other suitable material. The rotor
hub 18 includes one or more rotor blades 16 coupled to and
extending radially outward from the hub 18. As shown, the rotor hub
18 includes three rotor blades 16. However, in an alternative
embodiment, the rotor hub 18 may include more or less than three
rotor blades 16. The rotor blades 16 rotate the rotor hub 18 to
enable kinetic energy to be transferred from the wind into usable
mechanical energy, and subsequently, electrical energy.
Specifically, the hub 18 may be rotatably coupled to an electric
generator (not illustrated) positioned within the nacelle 14 for
production of electrical energy.
Referring to FIGS. 2 and 3, one of the rotor blades 16 of FIG. 1 is
illustrated in accordance with aspects of the present subject
matter. In particular, FIG. 2 illustrates a perspective view of the
rotor blade 16, whereas FIG. 3 illustrates a cross-sectional view
of the rotor blade 16 along the sectional line 3-3 shown in FIG. 2.
As shown, the rotor blade 16 generally includes a blade root 30
configured to be mounted or otherwise secured to the hub 18 (FIG.
1) of the wind turbine 10 and a blade tip 32 disposed opposite the
blade root 30. A body shell 21 of the rotor blade generally extends
between the blade root 30 and the blade tip 32 along a longitudinal
axis 27. The body shell 21 may generally serve as the outer
casing/covering of the rotor blade 16 and may define a
substantially aerodynamic profile, such as by defining a
symmetrical or cambered airfoil-shaped cross-section. The body
shell 21 may also define a pressure side 34 and a suction side 36
extending between leading and trailing ends 26, 28 of the rotor
blade 16. Further, the rotor blade 16 may also have a span 23
defining the total length between the blade root 30 and the blade
tip 32 and a chord 25 defining the total length between the leading
edge 26 and the trialing edge 28. As is generally understood, the
chord 25 may vary in length with respect to the span 23 as the
rotor blade 16 extends from the blade root 30 to the blade tip
32.
In several embodiments, the body shell 21 of the rotor blade 16 may
be formed as a single, unitary component. Alternatively, the body
shell 21 may be formed from a plurality of shell components. For
example, the body shell 21 may be manufactured from a first shell
half generally defining the pressure side 34 of the rotor blade 16
and a second shell half generally defining the suction side 36 of
the rotor blade 16, with such shell halves being secured to one
another at the leading and trailing ends 26, 28 of the blade 16.
Additionally, the body shell 21 may generally be formed from any
suitable material. For instance, in one embodiment, the body shell
21 may be formed entirely from a laminate composite material, such
as a carbon fiber reinforced laminate composite or a glass fiber
reinforced laminate composite. Alternatively, one or more portions
of the body shell 21 may be configured as a layered construction
and may include a core material, formed from a lightweight material
such as wood (e.g., balsa), foam (e.g., extruded polystyrene foam)
or a combination of such materials, disposed between layers of
laminate composite material.
Referring particularly to FIG. 3, the rotor blade 16 may also
include one or more longitudinally extending structural components
configured to provide increased stiffness, buckling resistance,
and/or strength to the rotor blade 16. For example, the rotor blade
16 may include a pair of longitudinally extending spar caps 20, 22
configured to be engaged against the opposing inner surfaces 35, 37
of the pressure and suction sides 34, 36 of the rotor blade 16,
respectively. Additionally, one or more shear webs 24 may be
disposed between the spar caps 20, 22 so as to form a box-beam spar
configuration (FIG. 3) or I-beam spar configuration (FIG. 4). The
spar caps 20, 22 are generally designed to control the bending
stresses and/or other loads acting on the rotor blade 16 in a
generally span-wise direction (a direction parallel to the span 23
of the rotor blade 16) during operation of a wind turbine 10.
Similarly, the spar caps 20, 22 may also be designed to withstand
the span-wise compression occurring during operation of the wind
turbine 10. As mentioned, the joint interface between the spar caps
20, 22 and the shear web 24 is a critical structural concern.
In FIG. 3, the spar caps 20, 22 are formed from rows 62 (FIG. 5) of
pultruded members 42 that essentially span the chord-wise aspect of
the spar cap 20, 22. In FIG. 4, the spar caps 20, 22 are formed
from rows 62 (FIG. 6) and columns 66 (FIG. 6) of the pultruded
members 42, wherein a plurality of the pultruded members 42 span
the chord-wise aspect of the spar cap.
It should be understood that the pultruded members 42 described
herein may be formed using any suitable pultrusion process. For
example, the pultruded members 42 are generally formed of
reinforced materials (e.g. fibers 44 or woven or braided strands)
that are impregnated with a resin material 46 and pulled through a
stationary die such that the resin material 46 cures or undergoes
polymerization through added heat or other curing methods. For
example, in certain embodiments, the heated die may include a mold
cavity corresponding to the desired shape of pultruded members 42
such that the mold cavity forms the desired shape in the completed
part. The pultruded members 42 may include an outer casing formed
using any suitable process, including but not limited to
pultrusion, thermoforming, or infusion.
The fibers 44 may include but are not limited to glass fibers,
nanofibers, carbon fibers, metal fibers, wood fibers, bamboo
fibers, polymer fibers, ceramic fibers, or similar. In addition,
the fiber material may include short fibers, long fibers, or
continuous fibers.
The pultruded members 42 may include different or varying materials
cured together with the resin material 46. More specifically, the
pultruded member 42 may include different types of fibers 44
arranged in a certain pattern. The fibers may include glass fibers,
carbon fibers, or any other suitable fiber material.
Further, the resin material 46 may include a thermoplastic material
or a thermoset material. A thermoplastic material generally
encompasses a plastic material or polymer that is reversible in
nature. For example, thermoplastic materials typically become
pliable or moldable when heated to a certain temperature and
solidify upon cooling. Further, thermoplastic materials may include
amorphous thermoplastic materials and/or semi-crystalline
thermoplastic materials. For example, some amorphous thermoplastic
materials may generally include, but are not limited to, styrenes,
vinyls, cellulosics, polyesters, acrylics, polysulphones, and/or
imides. More specifically, exemplary amorphous thermoplastic
materials may include polystyrene, acrylonitrile butadiene styrene
(ABS), polymethyl methacrylate (PMMA), glycolised polyethylene
terephthalate (PET-G), polycarbonate, polyvinyl acetate, amorphous
polyamide, polyvinyl chlorides (PVC), polyvinylidene chloride,
polyurethane, or any other suitable amorphous thermoplastic
material. In addition, exemplary semi-crystalline thermoplastic
materials may generally include, but are not limited to
polyolefins, polyamides, fluropolymer, ethyl-methyl acrylate,
polyesters, polycarbonates, and/or acetals. More specifically,
exemplary semi-crystalline thermoplastic materials may include
polybutylene terephthalate (PBT), polyethylene terephthalate (PET),
polypropylene, polyphenyl sulfide, polyethylene, polyamide (nylon),
polyetherketone, or any other suitable semi-crystalline
thermoplastic material.
Further, a thermoset material generally encompasses a plastic
material or polymer that is non-reversible in nature. For example,
thermoset materials, once cured, cannot be easily remolded or
returned to a liquid state. As such, after initial forming,
thermoset materials are generally resistant to heat, corrosion,
and/or creep. Example thermoset materials may generally include,
but are not limited to, some polyesters, esters, epoxies, or any
other suitable thermoset material.
The pultruded members 42 can be then joined together to form the
spar cap 20 via vacuum infusion, adhesive, semi-preg material,
pre-preg material, or any other suitable joining method. In this
joining process, a first end section of one or more webs 54-58,
such as a flexible fiber material (e.g., glass fiber) web, are
woven or interlaced between the pultruded members 42, and an
opposite end section of the webs 54-58 extends from the spar cap
20, 22 and are attached to the shear web 24, as described in
greater detail below.
In addition, it should be understood that the pultruded members 42
may have any suitable cross-sectional shape, such as the generally
rectangular shape depicted in the figures.
As shown in FIG. 3, each of the pultruded members 42 may define a
single row 62, with multiple rows 62 stacked atop one another and
joined together as discussed above. It should be understood that
the arrangement of the pultruded members 42 as shown in the figures
is given for illustrative purposes only and is not meant to be
limiting. For example, in further embodiments, the spar cap 20 may
be constructed of a single pultruded member 42. Alternatively, the
spar cap 20 may be constructed of multiple rows 62 and columns 66
of the pultruded members 42, as depicted in FIGS. 4 and 6-8.
Referring to FIGS. 3 and 4 in general, a wind turbine rotor blade
component 38 is depicted in one embodiment as a spar configuration
within the blade 16. The component includes a first structural
component 40 formed from a plurality of stacked pultruded members
42. In a particular embodiment illustrated in the figures, this
first structural component 40 may be, for example, a spar cap 20,
22. A second structural component 48 is fixed to the first
structural component 40 at a joint interface 52. As illustrated,
this second structural component 48 may be, for example, a shear
web 24. In FIG. 3, the first and second components 40, 48 form a
box-beam spar configuration, and in FIG. 4 the first and second
components 40, 48 form an I-beam spar configuration.
Referring to FIGS. 5 through 8 in general, one or more webs 54-60
are used to fix the first 40 and second 48 components together at
the joint interface 52. Each of the plurality of webs 54-60 has a
first section "a" (i.e., sections 54(a) through 60(a)) and a second
section "b" (i.e., sections 54(b) through 60(b)) extending across
the joint interface 52. In a first aspect, the present disclosure
encompasses an embodiment that utilizes a single web, wherein the
first section of this web 59(a) extends along and is bonded to a
top outer surface 68(a) of the stacked pultruded members 42 and the
second section of this web 59(b) extends across the joint interface
52 and is bonded (directly or indirectly) to the second structural
component 48 (e.g., shear web 24) using conventional adhesive or
resin bonding techniques.
In further embodiments, additional webs may be used. For example,
the first section of a second one of the webs 60(a) extends along
and is bonded to a bottom outer surface 68(b) of the stacked
pultruded members 42 with the second section of this web 60(b)
extending across the joint interface 52 and bonded to the second
structural component 48. With this embodiment, additional
"internal" webs may or may not be included. In other words, this
embodiment encompasses one or more "external" webs extending across
the joint interface 52 along the outer surfaces of the structural
components 40, 48.
Still referring to FIGS. 5 through 8 in general, other embodiments
include one or more additional "internal" webs underlying the
outermost webs 59, 60 at the joint interface. For example, one or
more additional webs (i.e., sections 54(a) through 58(a)) may be
bonded between at least two of the pultruded members 42 in the
first structural component 40 (e.g., spar cap 20), with the second
section (i.e., sections 54(b) through 58(b)) extending across the
joint interface 52 and bonded onto or into the second structural
component 48 (e.g., shear web 24) using conventional adhesive or
resin bonding techniques.
As mentioned, the improved joint interface structure 52 formed as
described above has particular usefulness when configured between a
spar cap 20, 22 and a shear web 24 in a box-beam (FIG. 3) or I-beam
(FIG. 4) spar, wherein the spar cap 20, 22 is formed by the
pultruded members 42 and the shear web is a unitary (FIGS. 5-7) or
multi-element (FIG. 8) component. It should be appreciated,
however, the joint interface structure 52 is not limited to this
use or location, and may be used between any structural components
within the wind turbine 10 or blade 16.
The webs 54-60 may be variously formed. In one embodiment, the webs
54-60 may be one or more layers of a woven or non-woven fabric
materials, such as a glass matt fabric, that is sufficiently
pliable so as to be woven between different ones of the pultruded
members 42, yet strong enough to form a rigid load-bearing joint
interface 52 between the components. The fabric layers 54-58 may be
bonded between the pultruded members 42 with an adhesive or resin
during formation of the first structural member 40, for example
during a vacuum thermo-forming process.
In a particular embodiment, the fabric material webs 54-58 may be
impregnated with a resin or adhesive and also serve a primary
purpose of adhering or bonding the pultruded members 42 together to
form the first structural member 40. In such embodiment, the webs
54-58 may extend entirely throughout the width and length of the
first structural member 40 between adjacent rows 62 and/or columns
66 of the pultruded members 42.
The second structural component 48 may be a unitary member, such as
the shear web 24 depicted in FIGS. 5 through 7, wherein the second
section of each of the plurality of webs 54(b) through 60(b)
extends alongside an outer surface 50 of the second structural
component. The second sections of multiple webs 54(b)-60(b) may
overlap along the outer surface 50 of the second structural
component 40, wherein such overlapped sections are bonded to each
other and to the outer surface 50 of the second structural
component 48.
In an alternate embodiment depicted for example in FIG. 8, the
second structural component 48 may be formed from a plurality of
bonded-together components 61, wherein the second section (b) of at
least one of the plurality of webs 54(b)-60(b) extends and is
bonded between two or more of the bonded-together components 60. In
a particular embodiment, the second structural component 48 may
also be formed from a plurality of pultruded components 60, as
discussed above with respect to the first structural component
40.
As discussed above, the pultruded members 42 may be arranged in
various configurations within the first structural component 40.
For example, as depicted in FIGS. 3 and 5, the pultruded members 42
may span across the entire chord-wise aspect of the first
structural component 40 and be arranged in stacked rows 62. The
first section of one or more of the plurality of webs 54(a)-58(a)
is bonded between two adjacent stacked rows 62. For example, the
first section of at least one of the webs 54(a)-58(a) may be bonded
between each of the stacked rows 62 of pultruded members 42, as
shown in FIG. 5.
As seen in FIGS. 6-8, the pultruded members 42 may be further
arranged in adjacent columns 66 within the first structural member
40, wherein the first section of at least one of the plurality of
webs 54(a)-54(b) is bonded between the pultruded members 42 at
different height positions in adjacent ones of the columns 66. In
addition, the webs may weave between the columns 66 at a different
height between adjacent columns 66.
It should be appreciated that the first section of a plurality of
the webs 54(a)-58(a) may weave between any combination of the
stacked rows 62 and columns 66 of pultruded members 42 within the
first structural component 40 (or the second structural component
48 if formed from pultruded components 60 or other separate
components).
Referring to FIGS. 6 and 7, in certain embodiments, the first
sections of multiple webs 54(a)-58(a) may be joined together within
the first structural component 40 to form an interconnected network
of the first sections. Alternatively, the first section of one or
more of the webs 54(a)-58(a) may include a plurality of branches
70, wherein each branch 70 extends between different pairs of the
pultruded members 42. It should be appreciated that the first
sections 54(a)-58(a) need not remain separated or distinct within
the matrix of pultruded members 42, but may attach or combine in
any pattern between the pultruded members 42.
The present invention also encompasses various methodologies for
fixing a first structural component 40, such as a spar cap 20, 22,
to a second structural component 48, such as a shear web 24, with a
plurality of webs 54-58, wherein the first structural component 40
is formed with a plurality of stacked pultruded members 42, as
discussed above. In a first aspect, the method includes bonding
(directly or indirectly) the first section of at least a first web
59(a) along and to a top outer surface 68(a) of the stacked
pultruded members 42, with the second section of this web 59(b)
extending across the joint interface 52 and bonded (directly or
indirectly) to the second structural component 48 (e.g., shear web
24) using conventional adhesive or resin bonding techniques. In an
additional embodiment, the first section of a second one of the
webs 60(a) extends along and is bonded to a bottom outer surface
68(b) of the stacked pultruded members 42 with the second section
of this web 60(b) extending across the joint interface 52 and
bonded to the second structural component 48.
Additional method embodiments may include bonding one or more
additional webs underlying the outermost webs 59, 60 at the joint
interface 52. For example, one or more additional webs (i.e.,
sections 54(a) through 58(a)) may be bonded between at least two of
the pultruded members 42 in the first structural component 40
(e.g., spar cap 20), with the second section (i.e., sections 54(b)
through 58(b)) extending across the joint interface 52 and bonded
onto or into the second structural component 48 (e.g., shear web
24) using conventional adhesive or resin bonding techniques. These
"internal" webs may be in addition to the external webs 59, 60.
In a particular embodiment of the method, the first structural
component 40 is a spar cap 20, 22, and the second structural
component 48 is a shear web 24.
The pultruded members 42 may be arranged in stacked rows 62 and
columns 66 in the spar cap 20, 22, wherein the method includes
weaving the first section of at least one of the plurality of webs
54(a)-58(b) between any combination of the stacked rows and columns
of pultruded members 42.
It should be appreciated that the various method embodiments may
include any of the aspects discussed above with respect to FIGS. 5
through 8.
This written description uses examples to disclose the invention,
including the best mode, and also to enable any person skilled in
the art to practice the invention, including making and using any
devices or systems and performing any incorporated methods. The
patentable scope of the invention is defined by the claims, and may
include other examples that occur to those skilled in the art. Such
other examples are intended to be within the scope of the claims if
they include structural elements that do not differ from the
literal language of the claims, or if they include equivalent
structural elements with insubstantial differences from the literal
languages of the claims.
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